In modern motor vehicles, systems which are controlled with gestures are increasingly used to control additional functions of the motor vehicle. Correspondingly, in modern motor vehicles, a plurality of different gesture recognition systems are applied. These are both contactless systems which recognize a gesture, for example via a camera, as well as systems which must be touched by a user in order to be able to recognize a gesture, such as, for example, touch-sensitive screens or optical finger navigation modules (also referred to as “OFN”). For all gesture recognition systems in a motor vehicle, it applies that a speed, above all, however, a direction of a gesture, is to be determined as precisely as possible. The current speed and direction of a gesture can be depicted by a speed vector. The direction thereof then represents the direction of the detected gesture and its length represents the speed of the gesture.
The object of the present invention is to create a method and a device to determine a speed vector for a gesture recognition system in a motor vehicle, by means of which the speed vector is able to be determined with a high level of accuracy and at the same time with high dynamics.
This object is solved according to the invention by a method or a device according to the independent claims.
Advantageous embodiments of the invention are subject matter of the dependent claims.
In order to achieve a particularly accurate and at the same time dynamic determination of a speed vector, two steps are initially provided to determine a speed vector for a sensory recognition system or gesture recognition system in a motor vehicle: a detection of movement data by a detection unit and a transmission of movement data to a processing unit in the form of vectors. A totalling of the vectors to form a total vector then occurs using the processing unit. This occurs until either the total vector reaches a predetermined minimum length or a predetermined number of vectors is added up. If the predetermined number of vectors is added up, and the predetermined length of the total vector is not reached, the speed vector is determined to be a zero vector. If the predetermined length of the total vector is reached, independently of the number of vectors added up, the speed vector is determined by an averaging of the information contained in the total vector. The averaging occurs here over the number of vectors totalled in the total vector. It is therefore virtually a type of standardization.
In other words, information concerning the detected movement data is therefore collected in the total vector and this collected information is evaluated as soon as it exceeds a determined quantity. If at this point in time, the content of the collected information is not sufficient for a reliable determination of the speed vector, this is determined to be zero. If the content of the information, however, is sufficient for a reliable determination of the speed vector, this determination is carried out by averaging. This has the advantage that, in the case of a slow speed of the gesture represented by the movement data, an accurate determination of the speed vector can occur by slow averaging. At the same time, in the case of a quick speed of the gesture represented by the movement data, an individual value consideration is effectively carried out and high dynamics are therefore achieved. Therefore, both slow and high speeds can each be determined with optimum accuracy and dynamics.
Advantageously, the totalling of the vectors to form a total vector by the processing unit occurs until either the total vector reaches a predetermined minimum length or a predetermined number of vectors is totalled, or the totalling is carried out within a predetermined time. This means the totalling is ended and the speed vector is determined as soon as a predetermined time has elapsed since the determination of the last speed vector. This has the advantage that the method also functions reliably with detection units which do not transmit movement data to the processing unit under certain circumstances. Then, for example, an infinitely long wait is prevented if the detection unit should malfunction or simply detect no movement data.
Furthermore, the speed vector is advantageously determined from the total vector as soon as two consecutive vectors to be totalled have a length of zero. This has the advantage that a continuation of the total vector in the case of a sudden stop of the gesture represented by the movement data, or, in the case of a touch-sensitive detection unit, also in the case of an interruption of the touching, is prevented. The speed vector is therefore also set to zero as soon as the speed of the gesture represented by the movement data decreases to zero.
In particular it is provided here that the speed vector is determined from the total vector, as soon as no vector is transmitted to the processing unit for a predetermined time. This has the previously referred to advantage in particular in the case in which the detection unit does not transmit any movement data as long as it does not detect any.
Advantageously, the speed vector is determined from the total vector as soon as the length of two consecutive vectors to be totalled differs by more than the minimum length. This has the advantage that large changes of speed can be recognized quickly and if necessary a checking of the length of the total vector can be omitted, which leads to quicker processing. In particular, abrupt changes of direction can therefore be quickly and precisely recognized.
It can furthermore be provided that the movement data are detected by a touch-sensitive detection unit. This has the advantage that an efficient determining of the speed vector is possible, as fundamentally only movement data are detected in a motor vehicle having several passengers if, in fact, a touching is also present, so a gesture is intended and therefore a gesture recognition is desired.
It is particularly advantageous that the movement data are detected by an optical finger navigation module. Such modules are suitable in a particular manner for an application of the vehicle, as only movement increments are detected here, such that a high level of accuracy in combination with high dynamics is particularly desirable in this case. In particular, such modules are particularly small, able to be applied in a versatile manner, and save energy such that they are provided for use in a motor vehicle.
Preferably it is provided that the movement data are transmitted at discrete, predetermined time intervals. This has the advantage that a further processing is very simple and the method can therefore be implemented technically in a particularly cost-effective manner.
Advantageously it is furthermore provided that the movement data are transmitted at variable time intervals. This has the advantage that communication bandwidths can be saved as no zero information can be transmitted and furthermore can be processed with detection units which only transmit movement data if they also detect movement data.
The invention also relates to a device to determine a speed vector for a gesture recognition system in a motor vehicle, wherein the device has equipment which is suitable to implement the previous method or its advantageous embodiments.
The preferred embodiments presented with regard to the method according to the invention and the advantages thereof apply accordingly for the device according to the invention.
Further features of the invention arise from the claims, the figures and the description of the figures. All features and feature combinations referred to above in the description as well as the features and feature combinations referred to in the description of the figures and/or in the figures alone are not only able to be applied in the respectively specified combination, but also in other combinations or alone.
The present invention is explained below by means of embodiments with reference to the enclosed drawings.